Pol Espargaro claimed first position in Friday free practice for the 125cc Spanish Grand Prix on his very last lap of the one-hour session at Jerez.
The Tuenti rider edged out Red Bull Ajo rider Marc Marquez by 0.121sec, with Efron Vasquez completing an all-Spanish - and all-Derbi - top three covered by just 0.247s.
Sandro Cortese was best of the rest, over one second behind Espargaro, while Qatar winner Nicolas Terol was fifth fastest for Aspar Aprilia.
Tito Rabat claimed sixth while last year's Spanish Grand Prix winner Bradley Smith, a disappointing eighth at Qatar after technical troubles, began his weekend with seventh – but nearly two-seconds from the top.
Fellow Briton Danny Webb suffered a slow lowside fall on his way to tenth.
Friday practice - Jerez:
1. Espargaro (Derbi) 1min 47.327sec
2. Marquez (Derbi) +0.121s
3. Vazquez (Derbi) +0.247s
4. Cortese (Derbi) +1.091s
5. Terol (Aprilia) +1.265s
6. Rabat (Aprilia) +1.723s
7. Smith (Aprilia) +1.943s
8. Moncayo (Aprilia) +2.013s
9. Iwema (Aprilia ) +2.112s
10. Webb (Aprilia) +2.288s